.shadow-pass {
  position: relative;
  overflow: hidden;
}

.shadow-pass::after {
  content   : '';
  position  : absolute;
  top       : 0;
  left      : -100%;
  width     : 100%;
  height    : 100%;
  background: linear-gradient(90deg, transparent, rgba(0, 0, 0, 0.05), transparent);
  animation : shadowPass 800ms ease-in-out infinite;
}

@keyframes shadowPass {
  0% {
    left: -100%;
  }

  100% {
    left: 100%;
  }
}